<template>

  <div class="app-container">

    <h2 style="text-align: center;">发布新课程</h2>

    <el-steps :active="1" process-status="wait" align-center style="margin-bottom: 40px;">
      <el-step title="填写课程基本信息"/>
      <el-step title="创建课程大纲"/>
      <el-step title="最终发布"/>
    </el-steps>

<el-form label-width="120px">

  <el-form-item label="课程标题">
    <el-input v-model="courseInfo.title" placeholder=" 示例：机器学习项目课：从基础到搭建项目视频课程。专业名称注意大小写"/>
  </el-form-item>

  <!-- 所属分类 TODO -->
<el-form-item label="课程分类">
  <el-select
    v-model="courseInfo.subjectParentId"
    placeholder="一级分类" @change="subjectLevelOneChanged">
    <el-option
      v-for="subject in subjectOneList"
      :key="subject.id"
      :label="subject.title"
      :value="subject.id"/>
  </el-select>
  <!-- 二级分类 -->
    <el-select v-model="courseInfo.subjectId" placeholder="二级分类">
    <el-option
        v-for="subject in subjectTwoList"
        :key="subject.value"
        :label="subject.title"
        :value="subject.id"/>
    </el-select>
</el-form-item>


  <!-- 课程讲师 TODO -->
<el-form-item label="课程讲师">
  <el-select
    v-model="courseInfo.teacherId"
    placeholder="请选择">
    <el-option
      v-for="teacher in teacherList"
      :key="teacher.id"
      :label="teacher.name"
      :value="teacher.id"/>
  </el-select>
</el-form-item>


  <el-form-item label="总课时">
    <el-input-number :min="0" v-model="courseInfo.lessonNum" controls-position="right" placeholder="请填写课程的总课时数"/>
  </el-form-item>

  <!-- 课程简介 TODO -->
  <!-- 课程简介-->
  <el-form-item label="课程简介">
      <tinymce :height="300" v-model="courseInfo.description"/>
  </el-form-item>
  

  <!-- 课程封面 TODO -->
<el-form-item label="课程封面">

  <el-upload
    :show-file-list="false"
    :auto_uplaod="true"
    :on-success="handleAvatarSuccess"
    :before-upload="beforeAvatarUpload"
    :action="BASE_API+'/eduoss/fileoss'"
    class="avatar-uploader">
    <img :src="courseInfo.cover">
  </el-upload>

</el-form-item>



  <el-form-item label="课程价格">
    <el-input-number :min="0" v-model="courseInfo.price" controls-position="right" placeholder="免费课程请设置为0元"/> 元
  </el-form-item>

  <el-form-item>
    <el-button :disabled="saveBtnDisabled" type="primary" @click="saveOrUpdate">保存并下一步</el-button>
  </el-form-item>
</el-form>
  </div>
</template>
<script>
import course from '@/api/edu/course'
import subject from '@/api/edu/subject'
import Tinymce from '@/components/Tinymce'//三方组件要声明
export default {
components: { Tinymce },
  data() {
    return {
      saveBtnDisabled: false, // 保存按钮是否禁用
      courseInfo:{
          title: '',
          subjectId: '',
          teacherId: '',
          lessonNum: 0,
          description: '',
          subjectParentId:'',  
          cover: '/static/1.png',
          price: 0
      },
      courseId:'',
      BASE_API: process.env.BASE_API, // 接口API地址
      teacherList:[],
      subjectOneList:[],
      subjectTwoList:[]
    }
  },
  watch: {
    $route(to, from) {
      console.log('watch $route')
      this.init()
    }
  },
  created() {
    if (this.$route.params && this.$route.params.id) {
            this.courseId = this.$route.params.id
            this.getInfo()
      }else{ 
       this.getOneSubject(); 
      }   
      this.getListTeacher();
  },

  methods: {
        init() {
          if (this.$route.params && this.$route.params.id) {
            const id = this.$route.params.id
            this.getInfo(id)(id)
          } else {
            // 使用对象拓展运算符，拷贝对象，而不是引用，
            // 否则新增一条记录后，defaultForm就变成了之前新增的teacher的值
            this.courseInfo = {}
            this.courseId = {}
            this.subjectOneList = {}
            this.subjectTwoList = {}

          }
      },
    getInfo() {
        course.getCourseInfo(this.courseId)
        .then(response => {
          console.log(this.courseId)
          this.courseInfo = response.data.courseInfoVo

          subject.getSubjectList()
          .then(response => {
            this.subjectOneList = response.data.list
            for(var i = 0; i < this.subjectOneList.length; i++){
              var oneSubject = this.subjectOneList[i];
              if(this.courseInfo.subjectParentId == oneSubject.id){
                  this.subjectTwoList = oneSubject.children;
              }
            }
          })
        })
    },
    handleAvatarSuccess(res,file){
          this.courseInfo.cover = res.data.url
    },
    beforeAvatarUpload(file){
         const isJPG = file.type === 'image/jpeg'
         const isPNG = file.type === 'image/png'
        const isLt2M = file.size / 1024 / 1024 < 2

        if (!isPNG) {
            this.$message.error('上传头像图片只能是 PNG 格式!')
        }
        if (!isLt2M) {
            this.$message.error('上传头像图片大小不能超过 2MB!')
        }
        return isPNG && isLt2M
    },
    subjectLevelOneChanged(value) {
        for (let i = 0; i < this.subjectOneList.length; i++) {
            if (this.subjectOneList[i].id === value) {
                this.subjectTwoList = this.subjectOneList[i].children
                this.courseInfo.subjectId=''//每次更改去除二级目录内容
        }
    }
    },
    getOneSubject() {
        subject.getSubjectList()
        .then(response=>{
           this.subjectOneList = response.data.list;
        })
    },
    getListTeacher(){
        course.getListTeacher()
        .then(response =>{
        this.teacherList = response.data.teachers
        })
    },
    addCourse() {
      course.addCourseInfo(this.courseInfo)
      .then(response => {
            this.$message({
                type: 'success',
                message: '添加课程信息成功'
            }) 
        this.courseId =  response.data.courseId
        this.$router.push({ path: '/course/chapter/'+response.data.courseId})
            console.log(response)           
      })  
    },
    updateCourse(){
        course.updateCouresInfo(this.courseInfo)
        .then(response =>{
            this.$message({
                type: 'success',
                message: '修改课程信息成功'
            }) 
        this.courseId =  this.courseId
        this.$router.push({ path: '/course/chapter/'+this.courseId})
            console.log(response)        
        })
    },
    saveOrUpdate() { 
      if(!this.courseInfo.id){
        this.addCourse()
      }else{
        this.updateCourse()
      }   
    }
  }
}
</script>
<style scoped>
.tinymce-container {
  line-height: 29px;
}
</style>